Apparatus for developing and/or fixing photographic printing material



Sept. 19, 1961 P. H. HELDENS 3,000,287

APPARATUS FOR DEVELOPING AND/OR FIXING PHQTOGRAPHIC PRINTING MATERIALFiled NOV. 28., 1955 1 2 Sheets-Sh eet 1 1 11 1111 1/1 1/1 1 11/11 1 111 1 fig IIIIIIII'I'III'I "IIIIIIIIII'II'IIIIIII'IIIIIIIII INVENTOR PETERHENRICUS HELDENS p 1961 P. H. HELDENS 3,000,287 APPARATUS, FORDEVELOPING AND/OR FIXING PHOTOGRAPHIC PRINTING MATERIAL Filed Nov. 28,1955 2 Sheets-Sheet 2 I, I H

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dig/d INVENTOR PETER HENRICUS HELDENS ATTO R N EYS United States PatentF 3,000,287 I APPARATUS FOR DEVELOPING AND/ORFIXING PHOTOGRAPHICPRINTING MATERIAL Peter Henricus Heldens, Venlo, Netherlands, assignorto Chemische Fabriek L. van der Grinten N.V., Venlo,

Netherlands, a Dutch limited liability company Filed Nov. 28, 1955, Ser.No. 549,493

Claims priority, application Netherlands Nov. 30, 1954 7 Claims. (CI.9589) 'The invention relates to an apparatus for developing and/ orfixing photographic printing material, particularly diazotype copies, inwhich the material is wetted on both sides with a thin layer of liquid,provided with two rotatable liquid-applying rollers, contacting eachother along generating lines and having surfaces impervious to liquid,their length being at least 30 times their diameter and their diameterat least 15 mm. Apparatus of this kind is known. "Generally the wettingof sheet material ononeside leads to strong curling of thematerial,especially in the production {ofdiazotype prints by the semi-wetprocess. In this technique therefore simultaneous wetting 'of both sidesis preferred. Thus'noncurling, flat copies are obtained. Naturally thisis;also achieved when simultaneously developing double-sided copies. Thepractice of photo-printing employs rollers of a diameter which ispractically always more than 15 mm. and the length of which'is" 30 andmore times their diameter. I i Y With such dimensions of the rollers, inthe usual apparatus the difficulty is encountered that dry spots mayappear on the material'transported between the applying rollers. This isattributed to the fact that the rollers do nothave uniform mutualcontact'along their. full length, that is to say that gaps areformedbetween them, owing to which the contact of the transportedmaterial witlnfi'foriexample, one of the rollersis. locally-lost, 'sothat locally no liquid is applied. Gaps of a width of an orderof'magnitude of :only'"0.lfmm.. are-"sufficient to bring thisabo'ut.

When sheet material is transported" between two' liquideapplyin'grollers between which a gap exists, said material being narrower thanthe length of the gap and thinner than itswidthjdifiicultiessometimes'arise, such as slipping; especially when, asris usually thecase,-the apparatus is not provided with special transportmeans.'Naturallyx-the phenomena in questionare less troublesome if the rollershave a soft: covering of sufficient thickness, -butrsuch: soft coveringshave other drawbacks; Such rollers run heavily, and thin sheetsofrelatively large dimensions. tend to crease while running through .theapparatus; -,In fact, in consequence of Ithe unequal localcontact-pressure between the rollers, "the pressure between the rollersand the material transported between :thein is locally diife'r'ent;Moreover, owing .to the varying degrees of compression of thesoftcover,=differ.encw arise in the active radius of the roller, which leadto difierences in tangential speed. v r The present invention overcomesthese difiiculties.

According to theinvention at least one ofthe rollers is'at leastpartially supported by theother roller and is lengthwise so flexiblethat, if-lying in a horizontal posi tio rr-andsupported'at the ends"only, it sags by-its own weightsubstantiallywalong a continuous orbroken curve, the sagof its lowest generatingrzline being at; least 0.1%

ice

of the length of the roller. A sagging of 0.8 is a high value inrelation to the average paper thickness, which amounts to approximately0.1 mm. 1

In the apparatus according to the invention one of the liquid-applyingrollers thus has a flexibility which permits this roller to adapt itselfcompletely or at least con siderably to the other roller or rollers withwhich it om operates. Owing to this the appearance of dry spots duringthe wetting of sheet material on both sides is avoided. Gaps becomesmaller or are fully eliminated so that the transport of sheet material,especially narrow, thin sheet material, is considerably improved. Thecontact-pressure between the liquid-applying rollers becomes moreuniform, so that, even when the flexible roller is made of softmaterial, the contact between the "rollers and the material transportedbetween them is practically the same in the circumferential directionalong the full length of the liquid-applying zone, and no differences intangential speed occur. The invention will be more fully described withrefer,- ence to the drawings.

FIGS. 1-3 are diagrammatic cross-sections, perpendicularly to the axesof the co-operating applying rollers of apparatus according to theinvention in different enibodiments. I

FIG. 4 illustrates diagrammatically the distribution of forces inapparatus accord'ng to FIG. 2.

FIGS. 5-10 show various embodiments of flexible liquid-applying rollersfor apparatus according to the in;- vention, in diagrammaticcross-sections.

, In'the FIGURESpl, 2, and 3, 1 and 2 are the liquid applying rollerswhich deliver in the applying zone 27 a thin layer of liquid 35, eg adiazot-ype developer, on to both sides of the material to be wet-ted 40,erg. diazo type paper of weight g./m. The rollers in the'ap paratusaccording to the FIGURES 1, 2, and 3 rotate in the directions indicatedby arrows.

In FIG. 1, liquid-applying roller 1 is rotatably mounted in trough 33,which is partly filled with liquid 35. The trunnions of roller 1 aresupported in bearings forming part of the frame 30. Liquid-applyingroller 2 is a flexible tube filled with liquid, eg a rubber hose,provided at its upper ends with trunnions 7. It rests on roller land isheld in position by trunnions 7 located in slots 32 in the frame 30.Both rollers have a length of cm. Roller '1 has a diameter of 3 0 mm.,roller 2 of 27 mm. Roller 1 is an ordinary roller, e.g. a solid, metalroller, which, in spite of its rigidity but in consequence of its ownweight and the weight of roller 2, sags somewhat, for example, by about0.2 mm. in the middle. Because. the tubular roller 2 can sag at least0.8 mm. per metre rollerlength, this roller can wholly follow thesagging of roller 1. The surface of roller 1 may be smooth or profiled.Roller 2 has a surface provided with capillaries, which receive aquantity of liquid from trough 33 via roller 1 when the apparatus is inoperation without any materials being transported between the tworollers. This quantity of liquid is delivered during the transport ofsheet material. Apparatus according to FIG. 1 is suitable for thewetting of sheets on both sides, the-top roller being permitted to fillits capillaries at intervals between the wetting of the sheets.

In the apparatus according to FIG. 2 two troughs, 33 and 34 are locatedat a short distance from each other. Bothare .partly filled, withliquid.35,, Liquid-applying forces acting on the rollers 1 and different forthe rollers 1 and 3 roller 1 is rotatably mounted in trough 33 andliquidtransmitting roller 3 is rotatably mounted in trough 34. Bothrollers are provided with trunnions, 6 and 8 respectively, which aresupported in stationary bearings. Liquid-applying roller 2 rests on therollers 1 and 3. It may be supported by means of trunnions, or may befreely supported. The sheet material 40 is transported between thetroughs 33 and 34 and the rollers 1 and 2. A thin layer ofliquid isapplied on both sides in zone 27. In this apparatus the rollers 1 and 2are continuously supplied with liquid, so that the sheet material 40 maybe along web. r t

In the apparatus according to FIG. 3 the troughs 33 and 134 are situatedat a greater distance from each other than in the apparatus according toFIG. 2. In both troughs liquid-transmitting rollers, 4 and 3respectively are rotatably mounted. They are provided with trunnions, 9and 8 respectively, which are supported in stationary bearings. Theliquid-applying rollers 1 and 2 rest on the liquid-transmittingv rollers3 and 4, and at the. same time rest against each other. One of theliquidapplying' rollers maybe flexible and the other may be an ordinaryrigid roller. Alternatively both rollers 1 and 2 may be flexiblerollers, but in that case at least one of them mustbe supported inbearings at its ends and must be rigid enough to. hold itself and at thesame time the other liquid-applying roller in their position ofcooperation with the liquid-transmitting rollers 3 and 4. Thus e.g. thetrunnions 6 of roller 1 may be supported. in stationary bearings. Roller2 may be freely supported; it may, however, also be provided withtrunnion's 7 which are supported in bearings. Liquid-applying rollers 1and 2 are continuously supplied with liquid by liquid-transmittingrollers 4 and 3. The surfaces of the liquid-applying rollers 1 and 2 ofapparatus according to FIGS. 2 and 3' may be smooth or profiled (i.e.grooved or the like). Also the surfaces of the liquid-transmittingrollers 3 and 4 may be smooth or profiled. For satisfactory functioningof the apparatus it is, however, necessary that a sufiicient quantity ofliquid is let through in the contact zones between liquidtransmittingand liquid-applying rollers. It is desirable to provide ampleopportunity for passage of the liquid in the contact zones betweenliquid-transmitting rollers and liquid-applying rollers, but to limitthe quantity of liquid let through. This may be done by means of adoctor device for doctoring off, the excess of liquid from the surfaceof the transmitting rollers. Such a doctor device is, for example, the"doctor roller indicated in dotted lines in FIG. 3'. By means of suchdoctor devices an almostunvarying liquid application may be obtained atvarying transport velocities of the sheet material.

FIG. 4' diagrammatically illustrates how, in an apparatus according toFIG. 2, roller 2 exerts pressure on both the lower rollers 1 and 3. Thevectors 22, 23, and and 24 illustrate. respectively what forces act onthe rollers 2, 1, and 3' owing to their own weights. The weight ofroller 2 may be resolved into the vectors 22a and 2212, which representthe forces with which the lower rollers are loaded by the weight ofroller 2. The total 3 are ultimately determined inmagnitude anddirection by the vectors 25 and 26'. Under the influence of these forcesthe lower rollers will sag somewhat in the direction of the vectors 25and 26. As the rollers 1 and 3 are supported at their ends, the saggingwill be greatest in the middle of the rollers and will decrease towardsthe ends. Generally this sagging will be different for the variousrollers, but at least i on the onehand and the roller 2 on the otherhand. Thus, gaps. appear in the liquid-applying zone 27 and in thecontact zone 28.

In an apparatus, according to FIG. 2, liquid-applying roller-f2 may beso compressible that its rollerprofile is not perfectlycircu-lar when itrests on the rollers 1 "and 3'." Preterabl y, however,- the flexibleroller in: the

apparatus according to the invention is elastically dewall of whichconsists of formable, though with sufficient rigidity substantially topreserve the circular roller profile.

FIG. 5 is an illustration of a longitudinal section of a rollerconsisting of a tube 11 with circular section. The tube may be made, forexample, of relatively soft rubber (e.g. 5070 Shore) and may have a wallthickness of a few millimetres. Such a tube is very flexible lengthwise,whereas its cross-section is rather rigid. In an apparatus according toFIG. 2 roller 2 works very well when it is made according to FIG. 5.Alternatively, tubes made of softer materials or rubber tubes with avery thin wall may be used- Thus, for example, it is possible toconstruct flexible, elastically deformable tubular rollers, withsuflicient rigidity substantially to preserve the circular rollerprofile, by means of a cover of flexible material, e.g. waterprooftissue: with an inner coating of a continuous row of rings, the outerdiameter of which is equal to the inner diameter of the cover. Whenusinga rubber tube with a wall thickness of 1 mm. or less, it is possible toobtain suflicient rigidity to preserve the circular roller profile byclosing the tube at its ends and charging it with air under pressure.

FIG. 6 illustrates a diagrammatical longitudinal section of a tubularroller the elastically deformable tube a cover 11 and a spiral springthe tube at the ends. Instead spring 12, separate rings may also be usedfor 12. Small plates 13 close of spiral internally supporting the cover11.

In apparatus for wetting sheet material on both sides theliquid-applying rollers also often have to provide for the transport ofthe material against a certain resistance. Often broad and longsheet-shaped material has to be transported through the apparatus, forexample, as a somewhat tensioned web. In order to obtain a sufiicientpull for this, the liquid-applying rollers either have to be pressedagainst each other with the necessary force, or have to be heavy enoughwhen they rest on or against each other by their own weight. In theapparatus according to the invention a suflicient pull between theliquid-applying rollers may easily be obtained by providing a tubularflexible liquid-applying roller with a filling. of a fluid substance orof solid bodies, which are movable in relation to one another at leastin a direction transverse to the tube. The fluid substance. may be aliquid, e.g. water, aqueous solutions, mercury and the like or a powderor granular material, such as sand, gunshot, and the like.

FIG. 7 illustrates in diagrammatic longitudinal section a tubular rollerwith elastically deformable cover 1 1', which is filled with pieces ofsolid material 15a and 15b which are movable in relation to each other.The

material is, for example, iron. Instead of using fairly large pieces ofsuch material, such as 15a and 15b, the tube may be filled with smallerpieces, such as the discs 16, as illustrated in FIG. 7A. I

The pieces 15:: and 15b are ball-and-socket jointed so thatthey canhinge in relation to each other, but cannot relatively move in adirection transverse to the axis of the tube. V

The rollers according to FIGS. 5, 6, and 7 not being provided withtrunnions, they are only suited for use in apparatus in which two otherrollers, such as the apparatus according to FIG. 2 or 3. In apparatusaccording to FIG. 1 it is necessary to give the flexible roller somebearing,- in order supported in bearings consist of a: tube providedwith a continuous: rigid core, with suflicient fredom of transversemovement. in relationto the tube wall and the they are supported by atleast tube filling respectively for preserving the desired degree of,deformability of the tube wall. These flexible rollers are easier tohandle than those without a core.. They can easily be taken out of theapparatus and stored with the ends of the core resting on supports. 1 f

In the flexible roller according to FlG. 8, of which a transverse crosssection is seen in FIG. 8A, the elastically deformable tube 11 is closedat its ends by plates 14. Core 10. with trunnions 7- has been passedthrough these plates and is fastened to them. The space between core10.and ithe .innenwall .of tube. 11 is partly filled with rings 17..-Theserings sarepr'ovided with holes" of a greaterdiameter than thatofcore 10. The outer diameter' of "therings issmaller than the innerdiameter of the tube 11'. Thus the, roller according to FIG..8i has goodtransverse deformability along its full length.

FIG. 9 illustrates a roller of a similar construction to that accordingto FIG. 8. The filling consists of granular bodies 18 and 19. Granules18 have a smaller size than granules 19 with equal specific gravity, orhave higher specific gravity with equal size. This flexible roller willthus apply a higher pressure against the other roller or rollers in themiddle than at its ends.

In the flexible roller according to FIG. 10 the space between core 10and the inner wall of tube 11 is partly filled with liquid 2.0. Whentube 11 is very flexible, its circular roller profile may be preservedby means of small discs 21, which are secured to core 10 at regularintervals. These small discs may be provided with passages so that thecompartments into which they divide the tube are interconnected.

In the flexible rollers according to the FIGS. 9 and 10 the spacesbetween core 10 and the inner wall of tube 11 may be completely filledwith the fluid substances 18, 19, and 20 respectively.

In order to obtain an even distribution of a thin layer of liquid onboth sides of the sheet material, the surfaces of the liquid-applyingrollers preferably have been or are provided with capillary recesses.Suitable recesses are, for example, pits, while grooves extendingtransversely to the axes of the rollers along their circumference arealso very suitable. Grooves of a depth-of, for example, 1 mm. and awidth of 0.15 mm. at distances of 0.45 mm. are very suitable.

When in the apparatus according to the invention the flexibility of theflexible rollers, and accordingly the uniformity of the applyingpressure in the liquid-applying zone between the liquid-applying rollersis increased, it is possible to decrease the applying pressure per unitof length of the rollers and yet retain sufficient pull for thetransport of broad and long sheet material as well as sufficientuniformity of liquid-application. Low applying pressure is advantageouswhen working with vulnerable materials, e.g. materials the surface ofwhich is coated with a soft film layer.

The invention is not limited to the illustrated embodiments; it may bevaried within the scope of the claims.

'I claim:

1. An apparatus for applying liquid evenly to both sides of a movingphotographic sheet material, comprising a plurality of horizontalrotatable rollers each having a diameter of at least 15 mm. and a lengthof many times its diameter, said rollers bearing one against anotheralong generating lines of their outer surfaces so that they rotatetogether, the outer surfaces of said rollers being substantiallyimpervious to liquid, and means for distributing liquid over saidsurfaces, at least one of said rollers having at least part of itsweight supported by another of said rollers along its line of contactwith the latter and being flexible and saggable bodily along said lineunder its own weight but comprising means maintaining itscircumferential profile traversing said line substantially uniformlyconvex at all locations along said line as said rollers are rotated,those two of said rollers forming between contiguous portions of theirrespective outer surfaces a passage for applying liquid to both sides ofsaid material, said one roller when supported horizontally at its endsonly having a sag along its lowest generating line. amounting to atleast 0.1% of its length. f I .2. apparatus for applying liquid evenlyto both sides. of a moving photographic sheet material, comprisingatleast three horizontal rotatable rollers bearing'one against anotheralong generating lines of their outer-surfaces so that they rotatetogether, the outer surfaces of said rollers beingsubstantiallyimpervious to liquid, and means for distributing liquidover said surfaces, at least qneofsaid rollers being mounted for freeverticalmovement andhaving parts ras weightsupported respectively by twoother ofsaidrollersalong-its lines of contact with the latter, saidsurfacesof said two rollers respectively carrying films of liquid tosaid lines, the outer surface of said one roller receiving a thin filmof liquid from said surface of one of said two rollers along one of saidlines, contiguous outer surface portions respectively of said one rollerand of the other of said two rollers forming therebetween along theother of said lines a passage for applying liquid to both sides of saidsheet material, said one roller being flexible and saggable bodily alongeach of said lines under its own weight but comprising means maintainingits circumferential profile traversing each of said lines substantiallyuniformly convex at all locations along said lines as said rollers arerotated, said one roller when supported horizontally at its ends onlyhaving a sag along its lowest generating line amounting to at least 0.1%of its length.

3. An apparatus for applying liquid evenly to both sides of a movingphotographic sheet material, comprising at least three horizontalrotatable rollers each having a diameter of at least 15 mm. and a lengthof many times its diameter, said rollers bearing one against anotheralong generating lines of their outer surfaces so that they rotatetogether, the outer surfaces of said rollers being substantiallyimpervious to liquid, and means for distributing liquid over saidsurfaces, at least one of said rollers having parts of its weightsupported respectively by two others of said rollers along its lines ofcontact with the latter, said surfaces of said two rollers respectivelycarrying films of liquid to said lines, the outer surface of one of saidrollers receiving a thin film of liquid for said surface of one of saidtwo rollers along one of said lines, contiguous outer surface portionsrespectively of said one roller and of the other of said two rollersforming therebetween along the other of said lines a passage forapplying liquid to both sides of said sheet material, said one rollerbeing flexible and saggable bodily along each of said lines under itsown weight but comprising means maintaining its circumferential profiletraversing each of said lines substantially uniformly convex at alllocations along said lines as said rollers are rotated, said one rollerwhen supported horizontally at its ends only having a sag along itslowest generating line amounting to at least 0.1% of its length. i

4. An apparatus as described in claim 3, said one roller comprising aflexible cylindrical tube containing a multiplicity of filling elementsdisplaceable relative to one another in directions transverse to thelength of said tube but relatively non-displaceable in the directionlengthwise thereof.

5. An apparatus as described in claim 3, said one roller comprising aflexible cylindrical tube containing a multiplicity of rigid fillingelements each of which has a cylindrical outer surface supporting alongitudinal section of the wall of said tube, said elements beingdisplaceable relative to one another in directions transverse to thelength of the tube but relatively non-displaceable in the directionlengthwise thereof.

6. An apparatus as described in claim 3, said one roller comprising afle 'ble cylindrical tube, a rigid core extending axially through saidtube, and a multiplicity of contiguous rigid filling elements lyingbetween the wall of said tube and said core, said elements restingfreely wear-.28

i 1- An apparatus as described in claim 6, said filling elemerits beingin the 'fo rrn of cylindrical rings surrounding said core andhaving asubstantially uniform outside divarneter; smaller than the insidediameter of said 'wall. References Cited the file of this patent fUNITED-STATES VPATENTS 42, 415 sweeter; Apr. '19, 1864 7 "580,509. V,Rochester Apr. 13, 1 897 654,194 Twohy July 24, 1900 Crompton Apr. 1,I913 5 Lawrence July-3; 1917 Top'hanl Feb. 12, 1929 Tailtz v Apr. 2519.33 lGundlach Apr, 19/ ,'1938 Nagels iet a1. -Q-AilgL 5, 111952Larnrhertse ;;Jan. 27, 1953 FOREIGN PATENTS V K "France Oct. 20, 1930Germany Jam 21; 193] France .4; Aug; 21, 1939 Great Britain Feb.. 26, 1941 France Dec. 11, 1943 France Mar. 31,1947 Great Britain Oct. 7, 1953."for" read from v Attesting'Offioer Commissioner of Patenlts UNITEDSTATES PATENT OFFICE f 1 CERTIFICATE OF CORRECTION Patent No. 3,000,287September 19 1961 Peter Henricus Heldens It is hereby certified thaterror appears in the above numbered patentrequiring correction and thatthe said. Letters Patent should read as v corrected below. A

Column 2, line 43, strike out "upper"; column 4, line 74," for-."fredqm" read freedom column 6, line44, for

Signed and'seal'ed this 20th day of February 1962.

(SEAL) Attest:

' ERNEST w. SWIDER. DAVID L. LADD A UNITED STATES PATENT OFFICECERTIFICATE OF CORRECTION Patent No. 3,000,287 I September 193,; 1961Peter Henricus Heldens It is herehy certified that error appears in theabove numbered patentrequiring correction and that the said LettersPatent should read as corrected below.

Column 2, line 43, strike out '.upper"; column 4 line 74,; for fredonfread freedom column 6 line 44, for "for read from Signed and sealed this20th day of February 1962.

(SEAL) Attest:

' Attesting Officer ERNEST W. SWIDER DAVID L. LADD Commissioner of Paton

